docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          assert all(stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
                     for stddev_type in stddev_types)
  
          C = self.COEFFS[imt]
          mean = self._compute_mean(C, rup.mag, dists.rrup)
          if isinstance(imt, SA) or isinstance(imt, PGA):
              # Convert from m/s**2 to g
              mean = mean - np.log(g)
          elif isinstance(imt, PGV):  # Convert from m/s to cm/s
              mean = mean + np.log(100.0)
          stddevs = self._get_stddevs(C, stddev_types, rup.mag,
                                      dists.rrup.shape[0])
  
          return mean, stddevs